Key to species of Righiodrilus (updated and modified from Feijoo & Gil 2010)

1. Spermathecae absent................................................................................. 2

- Spermathecae present................................................................................. 3

2. Male pores in xvii........................................................... R. muinane Feijoo & Gil, 2010

- Male pores with tubercula pubertatis in anterior region of xvii or middle ½ 16 – ½ 17.......... R. venancioi (Righi, 1982)

3. One pair of spermathecae.............................................................................. 4

- More than one pair of spermathecae..................................................................... 5

4. Spermathecae in viii–xix............................................................ R. dithecae (Righi, 1988)

- Spermathecae in xix–x..................................................... R. guahibo (Righi & Molina, 1994)

5. Four or six pairs of spermathecae....................................................................... 6

- Two or three pairs of spermathecae...................................................................... 7

6. Six pairs of spermathecae in ix–xi, 2 pairs per segment; clitellum in xvi–xxi; male pores in xvii/xviii................................................................................ R. sucunduris (Righi, Ayres & Bittencourt, 1976)

- Four pairs of spermathecae, in xiv–xvii; clitellum in xvi–xxiii; male pores in xviii/xix.................. R. gurupi n. sp.

7. Two pairs of spermathecae............................................................................. 8

- Three pairs of spermathecae............................................................................ 9

8. Spermathecae in 7/8 and 8/9.......................................................................... 10

- Not as above........................................................................................ 11

9. Spermathecae in 7/8, 8/9, 9/10......................................................................... 24

- Spermathecae in vi, vii and viii........................................................... R. viseuensis n. sp.

10. Clitellum in xv–xxi.................................................................................. 12

- Clitellum in another position.......................................................................... 13

11. Spermathecae in 9/10 and 10/11 ............................................ R. amazonius (Zicsi & Csuzdi, 1999)

- Spermathecae in another position.......................................................................16

12. Tubercula pubertatis in 1/2 xix–1/2 xx. Male pores in 19/20................................... R. uete (Righi, 1988)

- Tubercula pubertatis in xvii–xix. Male pores in 17/18....................................... R. cigges (Righi, 1970)

13. Male pores in 20/21................................................................................. 14

- Not as above........................................................................................15

14. Clitellum in xvii–xxiii; tubercula pubertatis in xix–xxiii.................................... R. freitasi (Righi, 1971)

- Clitellum in xvi–xiv; tubercula pubertatis in 1/2 xix–xxii.................................... R. aioca (Righi, 1975)

15. Male pores in 1/2 xix; clitellum in xvi–xxii; tubercula pubertatis in 1/2 xix–1/2 xxi................. R. tico (Righi, 1982)

- Male pores in xvii; clitellum in 1/2 xv–1/2 xxiii; tubercula pubertatis in xvii – xx........... R. andake Feijoo & Gil, 2010

16. Spermathecae in 8/9and 9/10 ......................................................................... 17

- Spermathecae in ix and x............................................................................. 18

17. Clitellum in xv–xxi...................................................................................19

- Clitellum in 1/2 xvi–1/2 xxii or xvi–xxii............................................... R. arapaco (Righi, 1982)

18. Male pores microscopic............................................................ R. oliveirae (Righi, 1982)

- Male pores not microscopic........................................................................... 21

19. Male pores in xvii....................................................................................20

- Male pores in 19/20............................................................... R. mairaro (Righi, 1982)

20. Tubercula pubertatis in xviii–xix..................................................... R. paolettii (Righi, 1984)

- Tubercula pubertatis in 1/2 xvi–1/2 xix.......................................... R. lebrijae Celis & Rangel, 2015

21. Clitellum in xv–xxii; tubercula pubertatis present.......................................................... 22

- Clitellum in xvi–xxiii; tubercula pubertatis absent................................................ R. moju n. sp

22. Male pores in xvi/xvii; tubercula pubertatis in 1/2 xvi–1/2 xviii............................................... 23

- Male pores in 17/18; tubercula pubertatis in 1/2 xvii–xx................................... R. ortonae (Righi, 1988)

23. Spermathecae in line with setae b....................................................... R. itajo (Righi, 1971)

- Spermathecae in line with setae d............................................... R. fontebonensis (Righi, 1988)

24. Male pores in xviii.................................................................................. 25

- Not as above....................................................................................... 26

25. Clitellum in xv–xxii; tubercula pubertatis in 1/2 xvii–1/2 xx.................................................. 27

- Clitellum and tubercula pubertatis in another position...................................................... 28

26. Clitellum in xv–xxi; tubercula pubertatis in 1/2 xvi–1/2 xix.................................................. 29

- Clitellum in xiv–1/2 xxii; tubercula pubertatis in 1/2 xvii–1/2 xx........................... R. inga Feijoo & Gil, 2010

27. Papillae pubertatis absent in xxi; tubercula as grooves with dark color in xviii, xix–xx... R. tocantinensis pola (Righi, 1984)

- Papillae pubertatis present in genital field 1/2 xvii–1/2 xx; papilla midventral in xxi.................................................................................................. R. tocantinensis tocantinensis (Righi, 1972)

28. Clitellum in 1/2 xiii–xxii; tubercula pubertatis in xvii–xx................................. R. marcusae (Righi, 1969)

- Clitellum in xv–xxiv; tubercula pubertatis in xvii–xxiii............................. R. schubarti (Righi et al., 1978)

29. Male pores in 16/17.............................................................. R. mucupois (Righi, 1970)

- Male pores in 17/18................................................................. R. tingus (Righi, 1971)